A colonoscopy is an internal examination of the colon (large intestine) and rectum, using an instrument called a colonoscope.

The colonoscope has a small camera attached to a flexible tube. Unlike sigmoidoscopy, which can only reach the lower third of the colon, colonoscopy examines the entire length of the colon.

You will lie on your left side with your knees drawn up toward your chest. After you have received a sedative and pain reliever, the colonoscope is inserted through the anus. It is gently moved into the beginning of the large bowel and sometimes into the lowest part of the small intestine.

Air will be inserted through the scope to provide a better view. Suction may be used to remove fluid or stool.

Because the health care provider gets a better view as the colonoscope is pulled back out, a more careful examination is done while the scope is being pulled out. Tissue samples may be taken with tiny biopsy forceps inserted through the scope. Polyps may be removed with electrocautery snares, and photographs may be taken.

Specialized procedures, such as laser therapy, may also be done.

You will need to completely cleanse your intestines. Your health care provider will give you instructions for doing this. This may include a combination of enemas, not eating solid foods for 2 or 3 days before the test, and taking laxatives. You will usually be told to stop taking aspirin, ibuprofen, naproxen, or other blood-thinning medications for several days before the test.

You will be asked to drink plenty of clear liquids for 1 - 3 days before the test. Examples of clear liquids are:

• Clean coffee or tea
• Fat-free bouillon or broth
• Gelatin
• Sports drinks
• Strained fruit juices
• Water

Images

Colonoscopy

• < Page
1 2
• >

Review Date: 11/23/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)